Reasons for failure and cancellation Tupolev Tu-144

1 reasons failure , cancellation

1.1 flights
1.2 limited routes
1.3 airframe test failures
1.4 decision go passenger service
1.5 cabin noise
1.6 seeking outside aid
1.7 compressor disc failure in 1980
1.8 economic inefficiency

reasons failure , cancellation
early flights

early flights in scheduled service indicated tu-144s extremely unreliable. during 102 flights , 181 hours of freight , passenger flight time, tu-144s suffered more 226 failures, 80 of them in flight. (the list included in tu-144 service record provided ussr british aircraft corporation-aérospatiale in late 1978, when requesting western technological aid tu-144, , incomplete.) eighty of these failures serious enough cancel or delay flight.

after inaugural flight, 2 subsequent flights, during next 2 weeks, cancelled , third flight rescheduled. official reason given aeroflot cancellation bad weather @ alma-ata; when journalist called aeroflot office in alma-ata local weather, office said weather there perfect , 1 aircraft had arrived morning. failures included decompression of cabin in flight on 27 december 1977, , engine-exhaust duct overheating causing flight aborted , returned takeoff airport on 14 march 1978.

alexei tupolev, tu-144 chief designer, , 2 ussr vice-ministers (of aviation industry , of civil aviation) had present in domodedovo airport before each scheduled tu-144 departure review condition of aircraft , make joint decision on whether released flight. subsequently, flight cancellations became less common, several tu-144s docked @ moscow s domodedovo international airport.

tu-144 pilot aleksandr larin remembers troublesome flight around 25 january 1978. flight passengers suffered failure of 22 24 onboard systems. 7 8 systems failed before takeoff, given large number of foreign tv , radio journalists , other foreign notables aboard flight, decided proceed flight avoid embarrassment of cancellation.

after takeoff, failures continued multiply. while aircraft supersonic en route destination airport, tupolev bureau s crisis centre predicted front , left landing gear not extend , aircraft have land on right gear alone, @ landing speed of on 300 km/h (190 mph; 160 kn). due expected political fallout, soviet leader leonid brezhnev notified of going on in air.

with accumulated failures, alarm siren went off after takeoff, sound , volume similar of civil defence warning. crew not figure way switch off siren stayed on throughout remaining 75 minutes of flight. eventually, captain ordered navigator borrow pillow passengers , stuff inside siren s horn. after suspense, landing gear extended , aircraft able land.

the final passenger flight of tu-144 on around 30 may 1978 involved valve failure on 1 of fuel tanks.

limited routes

only 1 commercial route (moscow city known alma-ata) ever used , flights limited 1 week, despite there being 8 tu-144s certified aircraft available , number of other routes suitable supersonic flights, suggesting soviet decision-makers had little confidence in tu-144 when passenger service began in 1977. considering high rate of technical failures reasoning sound. bookings limited 70–80 passengers or fewer flight, falling below both tu-144 s seating capacity , demand seats. on 55 scheduled flights, tu-144s transported 3,194 passengers, average of 58 passengers per flight. officials acutely aware of aircraft s poor reliability , fearful of possible crashes, soviet decision-makers deliberately limited flight frequency few allow them claim offering regular service, , limited passenger load minimize impact , political fallout of possible crash.

airframe test failures

a serious problem discovered when 2 tu-144s airframes suffered structural failures during laboratory testing prior tu-144 entering passenger service. details included in chapter in fridlyander s memoirs , mentioned bliznyuk et al. problem, discovered in 1976, may have been known prior testing; large crack discovered in airframe of prototype tu-144 (aircraft 68001) during stopover in warsaw following appearance @ 1971 paris air show.

the aircraft assembled parts machined large blocks , panels, many on 19 m (62 ft) long , 0.64 1.27 m (2.1 4.2 ft) wide. while @ time, approach heralded advanced feature of design, turned out large whole-moulded , machined parts contained defects in alloy s structure caused cracking @ stress levels below part supposed withstand. once crack started develop, spread many metres, no crack-arresting design feature stop it. in 1976, during repeat-load , static testing @ tsagi (russia s central aerohydrodynamic institute), tu-144s airframe cracked @ 70% of expected flight stress cracks running many metres in both directions origin.

later same year, test airframe subjected test simulating temperatures , pressures during flight. tu-144 placed in hyperbaric chamber , heated 130–150 °c (270–300 °f). contraction , expansion happen because of cooling during ascent , descent, heating during supersonic acceleration , cruise , because of pressure change high altitude (low outside pressure causing airframe expand) ground-level pressure (causing contract). airframe cracked in similar way during tsagi load testing.

while fatigue cracks of acceptable length normal in aircraft, found during routine inspections or stopped @ crack-arresting feature. aircraft fly acceptable cracks until repaired. tu-144 design opposite of standard practice, allowing higher incidence of defects in alloy structure, leading crack formation , propagation many metres.

decision go passenger service

the soviet leadership made political decision enter tu-144 passenger service in november 1977 despite receiving testing reports indicating tu-144 airframe unsafe , not airworthy regular service. aeroflot appears have thought little of aircraft did not mention in five-year plan 1976–1980. however, not airline executives decision , aeroflot reluctantly put tu-144 passenger service on 1 november 1977.

though decision cancel tu-144s passenger service came few days after tu-144d crashed during test flight on 23 may 1978, crash regarded last straw on mounting concerns reliability of tu-144. fact technical reason crash specific tu-144d fuel pump system , did not apply tu-144s did not help. decision pull tu-144s out of passenger service after merely 55 flights more attributable high incidence of failures during , before scheduled flights.

cabin noise

a problem passengers high level of noise inside cabin. noise came engines , air conditioning. in addition unique active heat insulation system, used flow of spent cabin air, described excessively noisy. passengers seated next each other have conversation difficulty, , seated 2 seats apart not hear each other when screaming , had pass hand-written notes instead. noise in of aircraft unbearable. alexei tupolev acknowledged problem foreign passengers , promised fix it, never had means so.

seeking outside aid

there unprecedented soviet requests western technological aid development of tu-144. request made despite not helping foster soviet technological prestige, 1 of key purposes of tu-144 programme. in 1977, ussr approached lucas industries, designer of engine control system concorde, requesting design of electronic management system of tu-144 engines, , asked bac-aérospatiale assistance in improving tu-144 air intakes. (the design of air intakes variable geometry , control system 1 of intricate features of concorde, contributing fuel efficiency. on half of wind-tunnel time during concorde development spent on design of air intakes , control system.) in late 1978, ussr requested wide range of concorde technologies, evidently reflecting broad spectrum of unresolved tu-144 technical issues. list included de-icing equipment leading edge of air intakes, fuel-system pipes , devices improve durability of these pipes, drain valves fuel tanks, fireproof paints, navigation , piloting equipment, systems , techniques acoustical loading of airframe , controls (to test against acoustic fatigue caused high jet-noise environment), ways reinforce airframe withstand damage, firefighting equipment, including warning devices , lightning protection, emergency power supply, , landing gear spray guards (aka water deflectors or mud flaps increase engine efficiency when taking off wet airstrips). these requests denied after british government vetoed them on ground same technologies, if transferred, employed in soviet bombers. soviet approaches reported in british mainstream press of time, such times.

compressor disc failure in 1980

on 31 august 1980, tu-144d (77113) suffered uncontained compressor disc failure in supersonic flight damaged part of airframe structure , systems. crew able perform emergency landing @ engels-2 strategic bomber base. on 12 november 1981, tu-144d s rd-36-51 engine destroyed during bench tests, leading temporary suspension of tu-144d flights. 1 of tu-144ds (77114, aka aircraft 101) suffered crack across bottom panel of wing.

economic inefficiency

finally, higher oil prices of 1970s starting catch soviet union. later in west, since late 1970s, commercial efficiency starting become factor in aviation development decision-making in ussr. tu-144 disappeared aeroflot published prospects, replaced ilyushin il-86, jumbo jet become soviet flagship airliner.

in late 1970s, soviet insiders intensely hopeful in conversations western counterparts of reintroducing tu-144 passenger service 1980 moscow olympic games, perhaps flights western europe, given aircraft s high visibility, apparently technical condition of aircraft weighed against such re-introduction token flights.

as discussed moon, economic efficiency alone not have doomed tu-144 altogether; continuation of token flights reasons of political prestige have been possible, if aircraft have allowed it, did not. tu-144 large extent intended , trumpeted symbol of soviet technological prestige , superiority.

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